One of the recent advances in the construction industry has been the use of foamed polystyrene sheets for insulation in homes and businessss. These sheets are typically attached to the walls or framework with construction mastic adhesives. The presently used mastic for bonding polystyrene foam is based on a random SBR. However, this mastic has low shear strength, making it less than desirable for many applications. One of the problems in developing a high shear strength mastic, e.g., one based on commercially available SBS block copolymers, is that the solvents typically employed with the mastic will also affect the polystyrene foam causing the foam to collapse. What is required is a high shear strength mastic that will not cause the polystyrene foam to collapse.